Hognose snakes are snakes that are recognized for their distinct upturned snouts, and exist within two distinct families within the Serpentes suborder. These families are Colubridae and Pseudoxyrhophiidae. Not all snakes within these families are Hognose Snakes. In fact, of the many genera within these families, Hognoses only make up a small number of species, within three specific genera – Heterodon, Leioheterodon and Lystrophis.
None of these genera are closely related at all and indeed they all exist in different areas around the world. One genus is native to South America, another in North America and the third are only known to exist in Madagascar.
These snakes, while often mistaken for venomous species due to their theatrical defensive behaviours, are mostly harmless to humans. Various species exhibit slight variations in appearance and behaviour, and there are many morphs amongst those that are bred in captivity.
Appearance & Characteristics of Hognose Snakes
Depending on the species, Hognose snakes can range from 15 to 45 inches in length, with males typically being significantly smaller than females. Their iconic upturned snout is used for digging in sandy soils, by making lateral swaying motions to purposefully move soil and often to hunt for an easy meal.
Their colouration is diverse, ranging from sandy colours with black and white markings to reds, greens and oranges depending on the species and locality. When threatened, some species will try their hand at mimicry, adjusting their features or behaviour to appear as a more aggressive and able species, capable of inflicting harm while defending.
Distribution – Location and Habitat
Hognose snakes are native to various parts of the world. Here are the different species in a table:
|H. kennerlyi (Mexican hognose snake)
|United States, Northern Mexico
|H. nasicus (Western hognose snake)
|H. nasicus gloydi (Gloyd’s hognose snake)
|H. platirhinos (Eastern hognose snake)
|H. simus (Southern hognose snake)
|L. geayi (Speckled hognose snake)
|L. madagascariensis (Malagasy giant hognose snake)
|L. modestus (Blonde hognose snake)
|L. dorbignyi (South American hognose snake)
|L. histricus (Jan’s hognose snake)
|L. pulcher (Tricolor hognose snake)
|L. semicinctus (Ringed hognose snake)
- Heterodon: This genus is primarily found in the United States and Northern Mexico. The snakes of this genus are known for their unique upturned snouts, which they use for digging in sandy soils. Their defensive behavior, known as thanatosis, involves playing dead when threatened. They exhibit a variety of colors and patterns, which help them blend into their surroundings.
- Leioheterodon: Native to Madagascar, the snakes of this genus are larger than their North American counterparts. They have a distinct appearance, with the Malagasy giant hognose snake being one of the largest species. Their upturned snouts are used for digging, and they are known to unearth the eggs of lizards. Their colouration varies, with some species like the speckled hognose snake having a brown or tan colour with dark speckling.
- Lystrophis: These are the South American hognose snakes. They are found across various parts of South America and are known for their vibrant patterns and colors. Like other hognose snakes, they have upturned snouts, which they use for burrowing. Their behaviour and diet are similar to the Heterodon species, but they are distinguished by their unique patterns and colorations.
The Lifestyle & Behaviour of Hognose Snakes
These snakes are diurnal, meaning they’re active during the day. They’re solitary creatures and are known for their dramatic defensive displays. When threatened, the most likely response is to attempt mimicry. They will try to take on the appearance of a Cobra, but raising their head off the ground and hissing, while at the same time flattening out their neck.
If mimicry fails, they might attempt to play dead instead. Emitting a foul smell and fecal matter from their cloaca, or even roll onto their backs with their tongues hanging out, feigning death to a tee.
They are snakes more likely to take flight rather than to try to fight off a foe directly. Most methods of threat avoidance include defensive postures or actions like those mentioned above, or to dig down into leaves to avoid discovery. They do carry venom however, and while rare, they may strike if they feel out of options. Their venom is mostly harmless to humans though, and they have no large fangs or method to deliver venom into their target.
Diet & Nutrition of Hognose Snakes
As these snakes live in different areas around the world, the diet does differ between the genera.
Heterodon species from North America for example are diurnal active foragers, that typically consume their prey live without any constriction or body pinning, primarily relying on only their jaws to subdue their prey.
For most Heterodon hognose snake species, the bulk of their diet is made up of rodents and lizards like frogs and salamanders. Heterodon platirhinos is an exception, specializing in feeding on toads, although other food items such as eggs and insects can make up a significant portion of its diet.
The South American Lystrophis Hognose snakes have a very similar diet to their North American cousins, but are also known to eat small, ground birds or nestlings. They are also more likely to eat rodents only in areas where amphibious prey is in short supply.
The Madagascan Leioheterodon Hognose snakes are more likely to be opportunistic with feeding on eggs. They will often unearth reptile eggs or even make a meal of bird eggs too. Larger species may be more likely to prey on small birds and small mammals too.
Predators & Threats to Hognose Snakes
Hognose snakes, particularly during their younger stages, are preyed upon by a variety of natural predators. Birds of prey such as hawks and eagles can spot and snatch them from above, while larger snakes, mammals like raccoons and foxes, and even some amphibians, such as bullfrogs, pose threats. Juveniles are especially vulnerable, often falling victim to these predators.
In addition to natural dangers, hognose snakes face several challenges due to human activities. Urbanization, agriculture, and deforestation lead to significant habitat loss, forcing snakes to cross roads, resulting in many becoming roadkill. Their unique appearance and defensive behaviors, while beneficial in the wild, often lead to misidentification and unnecessary killing by humans who mistake them for more venomous species.
The popularity of hognose snakes in the pet trade has led to over-collection from the wild, further impacting their populations.
Hognose Snakes Reproduction
Hognose snakes commence their mating rituals in spring, with males seeking out females using pheromones as indicators of readiness. This period often witnesses male hognose snakes wrestling each other to establish dominance for mating rights. After successful mating, females store the sperm internally, using it to fertilize their eggs when conditions are optimal. This is usually in the summer.
When ready, these oviparous snakes lay a clutch of 4 to 25 leathery eggs in secluded spots, ensuring warmth and humidity for development. The incubation of these eggs lasts between 50 to 60 days. As hatching approaches, the young snakes utilize a temporary ‘egg tooth’ (common with many birds and reptiles) to break through the eggshell.
These hatchlings are self-sufficient from the outset, shedding their skin for the first time within a couple of weeks and then embarking on their initial hunt. Young hognose snakes will reach sexual maturity around the age of 2 to 3 years, and will themselves then partake in the annual mating cycle.
Lifespan of Hognose Snakes
On average, they live for about 10-15 years in the wild. However, in captivity, where many of these challenges are mitigated, they can live up to 18 years with proper care. It’s essential to note that the lifespan can vary based on the species, with some living slightly longer or shorter than others within the range.
Population and Conservation
Most species of hognose snake are not endangered, and most of those that are listed on the IUCN Red List are considered ‘Least Concern’. The exception to this is the Southern hognose snake – Heterodon simus, which when last assessed by the IUCN in 2007, was classified as ‘Vulnerable’.
5 Fun Hognose Snakes Facts
- Hognose snakes can play dead to fool predators!
- They are considered nonvenomous even though they do have venom.
- Their upturned snout is perfect for digging, and they use this to find food.
- They can hiss loudly when threatened.
- Some hognose snakes use mimicry to pretend they are more dangerous snakes!